Various processes have been proposed for the production of hydrogen from water, some of which create oxygen as a by-product. One such "water-splitting" process produces hydrogen iodide as a part of a closed-cycle chain of chemical reactions and is disclosed in detail in U.S. Pat. No. 4,089,940, issued May 16, 1978 to John H. Norman et al. This process is based upon the Bunsen equation whereby sulphur dioxide, water and iodine are reacted to produce sulfuric acid and hydrogen iodide. This hydrogen iodide must then be broken down to H.sub.2 (the desired product) and to I.sub.2, which is recovered and returned to the main reaction.
It was found that hydrogen iodide could be economically decomposed in liquid form using a supported catalyst, such as ruthenium on a titania substrate or platinum on a barium sulphate substrate, as set forth in U.S. Pat. No. 4,258,026, issued Mar. 24, 1981 to Dennis R. O'Keefe et al. Although high conversion levels are possible with such a process and although it is considered to be a viable process, the use of such heterogeneous catalysis to decompose liquid HI, has displayed problems wherein the catalyst, particularly platinum, has a tendency to dissolve in liquid HI to a non-negligible degree, requiring some type of a catalyst recovery and remanufacture scheme. Although such catalyst recovery and remanufacture are commonplace in the chemical industry, they add to the complexity of the operation and to the operating and capital costs of the overall process. Accordingly, other equally efficient or more efficient processes were sought.